Question 11

The use of 4B5B encoding enables 100BaseTx Ethernet LANs to use a simpler form of line coding (i.e., NRZ-Inverted). However, by doing this, a 20% overhead penalty resulting in a reduced data throughput is incurred.

True

False

10 points

Question 12

For 802.3 LANs, a hybrid canceller transceiver device is used which enables full-duplex data communications

True

False

10 points

Question 13

What is correct regarding 100Base-TX?

		a. By using 4B5B coding, only 80% of the logical data sent represents real information (i.e., 20% of the bits are considered overhead)
		b. Can operate in full or half-duplex modes over two pair or single pair wire respectively.
		c. Operates over Cat5e UTP which enables a signaling rate of 125 MBaud
		d. All are correct

10 points

Question 14

In order to achieve 1Gbps (1GbE) over Cat5e cabling, what needs to be done?

		a. Use all four wire pairs in full-duplex
		b. Apply PAM-5 modulation to achieve N=2 (bits per symbol)
		c. Use hybrids that enable full-duplex transmission over a single wire pair
		d. All of the above

10 points

Question 15

Select the correct statement(s) regarding 802.11 WLANs.

		a. Operates over unlicensed ISM frequencies
		b. Implements spread spectrum or OFDM techniques for better noise resistance and spectral efficiency
		c. Uses CSMA/CA since collisions are always possible
		d. All of the above are correct